The present invention relates to liquid recovery containers and liquid ejection apparatuses.
As a liquid ejection apparatus ejecting liquid to a target, an inkjet type printer (hereinafter, simply referred to as a “printer”) ejecting ink to a recording medium is known. When necessary, the printer performs cleaning for removing the ink having increased viscosity from ink ejection nozzles, thus suppressing ink ejection problems.
In cleaning, a cap seals a nozzle forming surface in which the nozzles are formed. The airtight space defined between the nozzle forming surface and the cap (an in-cap space) is subjected to suction by a suction pump. This applies negative pressure acting in an ink ejection direction to the in-cap space. The negative pressure draws the ink, which has increased viscosity, from the nozzles.
After having been drawn from the nozzles by the suction pump, the ink is recovered by an ink recovery reservoir, or a liquid recovery container. The ink recovery reservoir includes a box-shaped recovery container having an upper opening and an ink absorption body accommodated in the recovery container. The ink recovery reservoir retains the ink drawn by the suction pump (hereinafter, simply referred to as the “waste ink”) in a state absorbed by the ink absorption body. Further, the ink recovery reservoir allows some solvent of the ink to volatilize from the upper opening of the recovery container, thus reducing the quantity of the retained ink. This improves the recovery efficiency of the ink recovery reservoir.
In recent cases, the above-described printer may use pigment ink or high-concentration ink for prolonging the life of an image printed by the printer or improving color expression of the image. Generally, in these cases, an element of the ink (for example, a pigment) easily condenses and solidifies due to volatilization or absorption of the solvent of the ink. Thus, if the ink recovery reservoir recovers the ink, the solidified ink element, or an ink residue, is deposited on a wall of the ink recovery reservoir (particularly, in the vicinity of a discharge port through which the waste ink is introduced into the recovery reservoir). The deposits hamper absorption of the waste ink and lower the performance of the ink recovery reservoir.
Conventionally, for the ink recovery reservoirs for recovering the aforementioned types of ink, techniques for preventing the ink residue from lowering the ink recovery performance have been proposed (for example, see Japanese Laid-Open Patent Publication No. 2004-34361). In the ink recovery reservoir described by the document, the waste ink discharged from the discharge port moves (diffuses) along the bottom surface of the ink recovery reservoir. The diffused ink is then absorbed by the ink absorption body. Since the diffused ink reduces the thickness of the ink residue, the contact area between the waste ink and the ink absorption body becomes relatively large. Therefore, compared to a case in which the waste ink is dropped on the ink absorption body from above and absorbed by the absorption body, the performance of the ink absorption body is maintained at a relatively high level. The performance of the ink recovery reservoir is thus prevented from being lowered.
However, the waste ink recovered by the ink recovery reservoir contains a large amount of bubbles generated from the air trapped in the in-cap space. This may cause the following problems.
When reaching the bottom surface of the recovery container, the bubbles in the waste ink may settle on the bottom surface of the recovery container and some of the bubbles may hamper diffusion of the ink. This may cause the ink to accumulate on the bottom surface of the recovery container. The solvent of the accumulated ink volatilizes from the upper opening of the recovery container, and the ink element solidifies. As a result, an ink residue is deposited on the bottom surface of the ink recovery reservoir, in the vicinity of the discharge port in particular, thus hampering ink absorption by the ink absorption body. This lowers the performance of the ink recovery reservoir.
Further, if the ink absorption body is exposed to the atmospheric air and an excessive amount of ink solvent volatilizes, a non-volatile element of the waste ink, such as the pigment, condenses and solidifies. The solidified element blocks pores of the ink absorption body, thus hampering permeability of the ink absorption body to the ink. Further, if the waste ink dries continuously, the non-volatile element of the ink condenses and the resulting condense increases in quantity, hampering permeation of the waste ink in the ink absorption body. This may cause overflow of the ink from the ink absorption body.